# wc-api-custom-meta
WordPress/WooCommerce plugin to support custom meta fields through the product API

A very simple plugin that allows you to view, create, update or remove custom meta fields when
managing products through the WooCommerce API v2.

It is necessary to install this plugin on the WC site providing the API.

I have raised a ticket asking whether this can ever be a core feature of WooCommerce,
but the ticket has been rejected:

https://github.com/woothemes/woocommerce/issues/7593

It may come back, but this plugin fills a gap in the meantime.

## Modifying Product Meta

To use it, add elements to the product array passed to the `products` POST entrypoint.
Each element is an array, with examples below. Both `custom_meta` and `remove_custom_meta`
elements are optional.

~~~php
$product = [
    'product' => [
        'title' => 'Foobar',
        ...
        'custom_meta' => [
            'my_custom_field_name' => 'my custom value',
            'my_other_custom_field_name' => 'my other custom value',
        ],
        'remove_custom_meta' => [
            'remove_all_instances_of_this_field_name',
            'remove_just_one_value_of_this_field_name' => 'this is the value',
        ],
    ]
]
~~~

That's it. Make sure those elements are in your REST API request, and this plugin is installed at the other end,
and you can set any meta fields you like, except for the protected fields (see below).

From version 0.7.0 metadata on variations is also supported:

~~~php
$product = [
    'product' => [
        'title' => 'Foobar',
        ...
        'variations' => [
            [
                'regular_price' => '9.50',
                'attributes' => [
                    [
                        'name' => 'Pack Size',
                        'slug' => 'pack-size',
                        'option' => '4-pack etc',
                    ],
                    // These custom meta fields will be added to the variations.
                    // When fetching variable products, the metafields will be retrieved
                    // for the variations.
                    'custom_meta' => [
                        'my_custom_variation_field_name' => 'my custom variation value',
                        'my_other_variation_custom_field_name' => 'my other custom variation value',
                    ],
                ],
            ],
        ],
    ]
]
~~~

I have not tested this with anything other than strings, so be aware that the behaviour storing other data structures
in metafields are *undefined* at present.

## Returning Product Meta

When retrieving a product, the custom product meta fields will be put into the "meta" field as an array when
retrieving a product through the API. This only works for capability 'manage_woocommerce' to help prevent
leakage of secure data.

The returned `meta` field will look something like this in structure:

~~~json
"meta":
{
    "test custom field": "Hi There!",
    "pv_commission_rate": "20%",
    "ISBN": "978-1910223260"
}
~~~

Both visible and hidden (with "_" prefixes) fields will be included in the list. All raw WooCommerce fields that 
are already present in some form in the product data will be filtered out, leaving only fields added by
third-party plugins or manually by the shop manager.